1. Field of the Invention
The present invention relates to a communication system, a path switching method, and a communication device, and more particularly to a communication system, a path switching method, and a communication device which provide an end-to-end redundant path of a communication path in an environment in which two or more kinds of redundant protocols are mixed together.
2. Description of the Background Art
IT service providing configurations using a communication network represented by a cloud service are increased. Since a service use response and continuity is important in an IT service using this communication network, a high quality and a high reliability are demanded for the communication network.
As a communication technology for realizing a communication path with the high quality and the high reliability, there is a packet transport. The packet transport represents a technique mainly used in a wide area network (WAN) of a communication carrier. The packet transport is configured by a transport edge node (TPE) that is arranged in an edge of a WAN, and holds communication devices of WAN users, a transport (TP) node that is arranged as a relay device of the WAN, and a network management system (NMS).
In the WAN configured by a packet transport, a connection oriented path is set for the TPE node and the TP node from the NMS. For that reason, the path can be set taking a bandwidth resource of the TP node into consideration to enable the high-quality communication to be provided. Also, in the packet transport, an operation administration and maintenance (OAM) and an autoprotection switching (APS) of the set path are standardized to provide the high-reliability communication path.
Also, as a higher reliability of a data center (DC) providing the cloud service, the DC may be geographically subjected to dual homing so that the IT service can be provided even if the overall DC cannot be used by a natural disaster.
Also, users who use the DC and the cloud service are frequently connected to the transport network by an Ethernet (registered network) access link. Therefore, in the network system providing the cloud service, all of the DC, the Ethernet access link, and the transport network are subjected to the dual homing so that the higher reliability of the system is expected.
Under the above background, there are techniques for realizing the network redundancy as disclosed in JP-A-2006-311254 and JP-A-2011-142383. JP-A-2006-311254 discloses the technique for providing a redundancy of a router and a redundancy of an access path to the router. JP-A-2011-142383 discloses, for example, a technique providing switching means when the dual-homed site and the user site are connected to each other by an access link and a transport path.